Resize alone doesn't work and I am forced to use RandomResizedCrop

vision
1

Not sure why Resize alone is not working? I am trying to avoid RandomResizedCrop

data_transforms = {
    'train': transforms.Compose([
        #transforms.RandomResizedCrop(input_size),
        transforms.Resize(input_size),
        transforms.RandomHorizontalFlip(),
        transforms.ToTensor(),
        #transforms.Normalize([0.485, 0.456, 0.406], [0.229, 0.224, 0.225])
    ]),
    'val': transforms.Compose([
        transforms.Resize(input_size),
        #transforms.CenterCrop(input_size),
        transforms.ToTensor(),
        #transforms.Normalize([0.485, 0.456, 0.406], [0.229, 0.224, 0.225])
    ]),
    
    'test': transforms.Compose([
        transforms.Resize(input_size),
        #transforms.CenterCrop(input_size),
        transforms.ToTensor(),
        #transforms.Normalize([0.485, 0.456, 0.406], [0.229, 0.224, 0.225])
    ])
}

The error is:

Traceback (most recent call last):
  File "patch_based_classifier.py", line 386, in <module>
    train_mean, train_std = get_mean_std(dataloaders_dict['train'])
  File "patch_based_classifier.py", line 377, in get_mean_std
    for data, _ in loader:
  File "/home/jalal/research/venv/dpcc/lib/python3.8/site-packages/torch/utils/data/dataloader.py", line 521, in __next__
    data = self._next_data()
  File "/home/jalal/research/venv/dpcc/lib/python3.8/site-packages/torch/utils/data/dataloader.py", line 1203, in _next_data
    return self._process_data(data)
  File "/home/jalal/research/venv/dpcc/lib/python3.8/site-packages/torch/utils/data/dataloader.py", line 1229, in _process_data
    data.reraise()
  File "/home/jalal/research/venv/dpcc/lib/python3.8/site-packages/torch/_utils.py", line 434, in reraise
    raise exception
RuntimeError: Caught RuntimeError in DataLoader worker process 0.
Original Traceback (most recent call last):
  File "/home/jalal/research/venv/dpcc/lib/python3.8/site-packages/torch/utils/data/_utils/worker.py", line 287, in _worker_loop
    data = fetcher.fetch(index)
  File "/home/jalal/research/venv/dpcc/lib/python3.8/site-packages/torch/utils/data/_utils/fetch.py", line 52, in fetch
    return self.collate_fn(data)
  File "/home/jalal/research/venv/dpcc/lib/python3.8/site-packages/torch/utils/data/_utils/collate.py", line 84, in default_collate
    return [default_collate(samples) for samples in transposed]
  File "/home/jalal/research/venv/dpcc/lib/python3.8/site-packages/torch/utils/data/_utils/collate.py", line 84, in <listcomp>
    return [default_collate(samples) for samples in transposed]
  File "/home/jalal/research/venv/dpcc/lib/python3.8/site-packages/torch/utils/data/_utils/collate.py", line 56, in default_collate
    return torch.stack(batch, 0, out=out)
RuntimeError: stack expects each tensor to be equal size, but got [3, 299, 299] at entry 0 and [3, 299, 493] at entry 155
2

Following the instructions from @ptrblck solved the issue.

data_transforms = {
    'train': transforms.Compose([
        #transforms.RandomResizedCrop(input_size),
        transforms.Resize((input_size, input_size)),
        transforms.RandomHorizontalFlip(),
        transforms.ToTensor(),
        #transforms.Normalize([0.485, 0.456, 0.406], [0.229, 0.224, 0.225])
    ]),
    'val': transforms.Compose([
        transforms.Resize((input_size, input_size)),
        #transforms.CenterCrop(input_size),
        transforms.ToTensor(),
        #transforms.Normalize([0.485, 0.456, 0.406], [0.229, 0.224, 0.225])
    ]),
    
    'test': transforms.Compose([
        transforms.Resize((input_size, input_size)),
        #transforms.CenterCrop(input_size),
        transforms.ToTensor(),
        #transforms.Normalize([0.485, 0.456, 0.406], [0.229, 0.224, 0.225])
    ])
}